The invention relates to a method of transmitting or storing, over an interference affected channel, digital audio signals, wherein transmission errors are detected at the receiving end and corrected if necessary or masked, with the masking being effected in that the interfered-with signal section is muted or replaced by a signal section preceding the interfered-with signal section in the same channel or by a synchronous, not interfered-with signal section of an adjacent channel. Such a method is disclosed in German Patent DE 3,638,922.C2.
In digital audio signal transmissions and storage, the received and read-out audio signals, if they contain bit errors, may either be not decodable at all or not decodable in part after all error detection and error correction methods have been exhausted. In that case, it is the custom to switch to a decoder for muting over a broad band in such a way that for a certain time period the entire signal is set at 0. In the case of digital audio signals transmitted by radio, this case occurs relatively frequently at the fringes of the reception area which is extremely annoying particularly in connection with mobile reception. The same applies for audio signal storage if the tape material or audio heads are worn to a degree that exceeds a tolerance value.
To reduce the annoying effect of missing signals in radio transmissions, German Patent DE 3,638,922.C2 discloses a mutual offset in time between the left and right stereo channels and, if there is an uncorrectable signal interference, placing the complementary stereo information transmitted at an earlier or later point in time instead of the interfered-with original information. Although the complementary stereo information is not identical with the associated, interfered-with original information, but is connected with it only by way of left-right correlation, such a substitution is acceptable in any case for a short period of time since direction and distance perception as well as the perception of spatial relationships are subject to a certain inertia in the human ear. However, if such a masking technique is employed for a longer period of time, the stereophonic impression is lost, since the masking always covers the full bandwidth of the interfered-with signal and therefore also replaces spectral signal components that did not suffer interference.